FixpointType: defines the various types and
associated printing functions (including for the DOT output);

FixpointStd: implements the Kleene-Bourdoncle
iteration technique [Bou93] (combined with
working-set algorithm) for solving equations described
explicitly by an hypergraph, and offers base functions for the
more sophisticated techniques;

FixpointGuided: implements the Gopan-Reps guided
iteration technique [GR07] for equations described
explicitly by an hypergraph;

FixpointDyn: exploits an implicit description
(under the form if a successor function) of the equation graph,
which is then explored dynamically by alternating propagation
phase (to detect newly non-empty variables) and
upto-convergence-iteration phase.